*{
    padding: 0;
    margin: 0;
    box-sizing: border-box;
}
.main_title{
    width: 100%;
    height: 132px;
}
.background{
    width: 100%;
    height: 38px;
    background-color: #efefef;
}
.main_title_top{
    width: 1050px;
    height: 38px;
    margin: auto;
}
.main_title_top_ps{
    float: left;
    color: #000;
    font-size: 14px;
    line-height: 38px;
}
.main_title_top_right{
    float: right;
    width: 140px;
    list-style-type: none;
}
.main_title_top_right_left,.main_title_top_right_right{
    float: left;
}
.main_title_top_right_left{
    width: 70px;
    border-right: 1px solid #646464;
    margin-top: 12px;
}
.link{
    text-decoration: none;
}
.main_title_top_right_left_p{
    color: #000;
    font-size: 14px;
    line-height: 15px;
}
.main_title_top_right_right_p{
    color: #000;
    font-size: 14px;
    line-height: 38px;
    padding-left: 10px;
}
.main_title_top::after,.main_title_top_right::after,.main_logo_nav::after,.main_title_bottom::after,.main_title_bottom_uls::after{
    content: "";
    height: 0;
    visibility: hidden;
    display: block;
    clear: both;
}
.main_title_bottom{
    width: 1050px;
    height: 94px;
    margin: auto;
}
.main_title_bottom_image{
    margin-top: 30px;
    width: 303px;
    height: 45px;
    float: left;
}
.main_title_bottom_uls{
    list-style-type: none;
    float: right;

}
.main_title_bottom_uls_lis{
    float: left;
    width: 94px;
    height: 94px;
    line-height: 94px;
    text-align: center;
}
.main_title_bottom_uls_liss{
    float: left;
    line-height: 94px;
    width: 94px;
    height: 94px;
    text-align: center;
}
.main_title_bottom_uls_lis_p{
    color: #000;
    font-size: 14px;
}
.main_title_bottom_uls_lisd{
    height: 94px;
    width: 94px;
    text-align: center;
    line-height: 94px;
    float: left;
}
.main_title_bottom_uls_lisd:hover,.main_title_bottom_uls_lis:hover{
    border-bottom: 7px solid #3c9cd3;
}
.main_logo{
    background-image: url("../05-练习页面响应式/-3.png");
    background-position-x: 100%;
    width: 100%;
    height: 937px;
    padding-top: 70px;
}
.main_logo_image{
    width: 968px;
    height: 471px;
    display: block;
    margin: auto;
}
.main_logo_nav{
    list-style-type: none;
    width: 762px;
    margin: auto;
}
.main_logo_nav_lis{
    width: 220px;
    height: 219px;
    border: 2px dashed #ebebeb;
    margin-top: 36px;
    float: left;
    margin-right: 34px;
}
.main_logo_nav_lis_image{
    width: 57px;
    height: 50px;
    display: block;
    margin: auto;
    margin-top: 30px;
}
.main_logo_nav_lis_p{
    width: 173px;
    height: 40px;
    text-align: center;
    border-bottom: 1px dashed #cbcbcb;
    font-size: 16px;
    color: #439ea3;
    margin-left: 22px;
    margin-top: 12px;
}
.main_logo_nav_lis_ps{
    font-size: 12px;
    color: #8c8c8c;
    line-height: 22px;
    margin-top: 20px;
    width: 198px;
    margin-left: 14px;
}
.main_background{
    width: 100%;
    height: 488px;
    background-color: #e6e8e9;
}
.main_content{
    width: 1050px;
    height: 488px;
    margin: auto;
    padding-top: 54px;
}
.main_content::after{
    content: "";
    height: 0;
    visibility: hidden;
    display: block;
    clear: both;
}
.main_content_title{
    font-size: 18px;
    color: #000;
    text-align: center;
}
.main_content_imgs{
    width: 257px;
    height: 10px;
    display: block;
    margin: auto;
    margin-top: 13px;
}
.main_content_p{
    font-size: 14px;
    color: #666666;
    line-height: 24px;
    width: 826px;
    margin: auto;
    margin-top: 35px;
    text-indent: 2em;
}
.main_content_img{
    width: 1050px;
    height: 167px;
    background-color: #ffffff;
    margin: auto;
    padding-top: 4px;
    margin-top: 64px;
}
.main_content_img_one{
    width: 51px;
    height: 159px;
    margin-left: 4px;
}
.main_content_img_two,.main_content_img_four,.main_content_img_theer{
    width: 282px;
    height: 159px;
    margin-right: 18px;
}
.main_content_img_five{
    width: 72px;
    height: 159px;
}
.main_content2{
    height: 650px;
    width: 100%;
    padding-top: 90px;
}
.main_content2_background{
    background-color: #a4d1ee;
    height: 468px;
    width: 100%;
    margin-top: 46px;
}
.main_content2_background_uls{
    list-style-type: none;
    width: 1050px;
    padding-top: 60px;
    margin: auto;
}
.main_content2_background_uls_lis{
    width: 104px;
    height: 36px;
    float: left;
}
.main_content2_background_uls_liss{
    width: 104px;
    height: 36px;
    margin-right: 6px;
    float: left;
}
.main_content2_background_uls_lis_p{
    font-size: 14px;
    color: #ffffff;
    text-align: center;
    line-height: 36px;
}
.main_content2_background_uls_lis:hover,.main_content2_background_uls_liss:hover{
    background-image: url("../05-练习页面响应式/-12.png");
}
.main_content2_background_uls_lis_p:hover{
    color: #7fc1f0;
}
.main_content2_background_uls::after,.main_content2_background_bottom::after{
    content: "";
    height: 0;
    display: block;
    clear: both;
    visibility: hidden;
}
.main_content2_background_bottom{
    width: 1050px;
    margin: auto;
}
.main_content2_background_bottom_uls{
    list-style-position: inside;
    list-style-image: url("../05-练习页面响应式/-13.png");
    float: left;
}
.main_content2_background_bottom_uls_lis{
    width: 664px;
    height: 54px;
    border-bottom: 1px dashed #f6fbfd;
    line-height: 54px;
}
.main_content2_background_bottom_uls_lis_link{
    text-decoration: none;
    font-size: 14px;
    color: #ffffff;
    margin-left: 30px;
}
.main_content2_background_bottom_uls_lis_link_spans{
    float: right;
    margin-right: 80px;
}
.main_content2_background_bottom_img{
    float: right;
    margin-top: 20px;
}
.main_content3{
    height: 645px;
    width: 1100px;
    margin: auto;
    padding-top: 100px;
}
.kong{
    clear: both;
}
.main_content3_left{
    width: 470px;
    height: 468px;
    margin-top: 30px;
    float: left;
}
.main_content3_left_erwei{
    width: 141px;
    height: 188px;
    border: 1px solid #ebebeb;
    float: left;
}
.main_content3_left_erwei_img{
    width: 109px;
    height: 109px;
    display: block;
    margin: auto;
    margin-top: 15px;
}
.main_content3_left_erwei_ps{
    font-size: 12px;
    color: #030303;
    line-height: 21px;
    text-align: center;
    margin-top: 14px;
}
.main_content3_left_uls{
    float: left;
    list-style-type: none;
}
.main_content3_left_uls_lis{
    margin-left: 26px;
    height: 18px;
    margin-bottom: 15px;
}
.main_content3_left_uls_lis_img{
    width: 22px;
    height: 18px;
    float: left;
}
.main_content3_left_uls_lis_p{
    float: left;
    font-size: 14px;
    color: #747474;
    margin-left: 15px;
    line-height: 18px;
}
.main_content3_left_image{
    width: 430px;
    height: 196px;
    margin-top: 32px;
}
.main_content3_left::after{
    content: "";
    height: 0;
    visibility: hidden;
    display: block;
    clear: both;
}
.main_content3::after{
    content: "";
    height: 0;
    visibility: hidden;
    display: block;
    clear: both;
}
.main_content3_right{
    float: left;
    margin-top: 24px;
}
.main_content3_right_nav{
    margin-bottom: 18px;
}
.main_content3_right_nav_content{
    font-size: 14px;
    color: #666666;
}
.main_content3_right_nav_text{
    width: 630px;
    height: 34px;
    border: 1px dashed #d4d2d2;
    background-color: #f9f8f8;
    margin-top: 5px;
}
.main_content3_right_nav_texts{
    width: 630px;
    height: 120px;
    border: 1px dashed #d4d2d2;
    background-color: #f9f8f8;
    margin-top: 6px;
}
.main_content3_right_nav_tijiao{
    width: 94px;
    height: 30px;
    background-color: #3c9cd3;
    border: 0px;
    margin-top: 4px;
    color: #ffffff;
}
.main_footer{
    height: 129px;
    width: 100%;
}
.main_footer_top{
    height: 94px;
    background-color: #3c9cd3;
}
.margin{
    width: 214px;
    margin: auto;
    padding-top: 20px;
}
.main_footer_top_p{
    color: #ffffff;
    float: left;
    font-size: 12px;
    margin-right: 18px;
}
.main_footer_top_img{
    float: left;
    margin-right: 21px;
    width: 24px;
    height: 20px;
}
.main_footer_top_uls{
    width: 400px;
    margin: auto;
    list-style-position: inside;
    color: #ffffff;
    font-size: 12px;
    margin-top: 24px;
}
.main_footer_top_uls_lis{
    float: left;
    margin-right: 6px;
}
.main_footer_top_uls_lis_link{
    text-decoration: none;
    color: #ffff;
    font-size: 12px;
    margin-left: -8px;
}
.main_footer_top_uls_liss{
    list-style-type: none;
    float: left;
    margin-right: 6px;
}
.main_footer_bottom{
    background-color: #1c1b29;
    height: 35px;
}
.main_footer_bottom_p{
    color: #ffffff;
    font-size: 12px;
    margin: auto;
    line-height: 35px;
    width: 534px;
}
.margin::after,.main_footer_top_uls::after{
    content: "";
    height: 0;
    visibility: hidden;
    display: block;
    clear: both;
}


@media screen and (max-width:640px){
    *{
        padding: 0;
        margin: 0;
        box-sizing: border-box;
    }
    .main_title{
    width: 100%;
    height: 132px;
    }
    .background{
        width: 100%;
        height: 38px;
        background-color: #efefef;
    }
    .main_title_top{
        width: 520px;
        height: 38px;
    }
    .main_title_top_ps{
        float: left;
        color: #000;
        font-size: 14px;
        line-height: 38px;
        margin-left: 10px;
    }
    .main_title_top_right{
        float: right;
        width: 140px;
        list-style-type: none;
    }
    .main_title_top_right_left,.main_title_top_right_right{
        float: left;
    }
    .main_title_top_right_left{
        width: 70px;
        height: 15px;
        border-right: 1px solid #646464;
        margin-top: 12px;
    }
    .link{
        text-decoration: none;
    }
    .main_title_top_right_left_p{
        color: #000;
        font-size: 14px;
        line-height: 15px;
    }
    .main_title_top_right_right_p{
        color: #000;
        font-size: 14px;
        line-height: 38px;
        padding-left: 10px;
    }
    .main_title_top::after,.main_title_top_right::after,.main_logo_nav::after.main_title_bottom::after{
        content: "";
        height: 0;
        display: block;
        clear: both;
        visibility: hidden;
    }
    .main_title_bottom{
        width: 520px;
        height: 94px;
        margin: auto;
    }
    .main_title_bottom_image{
        margin-top: 30px;
        width: 303px;
        height: 45px;
        float: right;
    }
    .main_title_bottom_uls{
        width: 94px;
        height: 50px;
        list-style-type: none;
        float: left;
        margin-top: 28px;
        margin-left: 0px;
        position: relative;
    }
    .main_title_bottom_uls_lis,.main_title_bottom_uls_lisd{
        width: 94px;
        height: 40px;
        line-height: 35px;
        visibility: hidden;
        float: none;
    }
    .main_title_bottom_uls:hover .main_title_bottom_uls_lis,.main_title_bottom_uls_lisd{
        visibility: inherit;
        /* border: 1px solid #000; */
        background-color: #49e4ec;
    }
    .main_title_bottom_uls_lis:hover,.main_title_bottom_uls_lisd:hover{
        border: 1px solid #000;
    }
    .main_logo{
        background-image: url("../05-练习页面响应式/-3.png");
        background-position-x: 100%;
        width: 100%;
        height: 370px;
        padding-top: 35px;
    }
    .main_logo_image{
        width: 300px;
        height: 136px;
        display: block;
        float: none;
        position: absolute;
        left: 240px;
    }
    .main_logo_nav{
        list-style-type: none;
        width: 0px;
        margin: auto;
        float: left;
    }
    .main_logo_nav_lis{
        width: 190px;
        height: 136px;
        border: 2px dashed #a7a4a4;
        margin-top: 0px;
        float: none;
        margin-right: 0px;
        margin-left: 10px;
    }
    .main_logo_nav_lis1{
        margin-top: 16px;
    }
    .main_logo_nav_lis2{
        position: relative;
        left: 230px;
        top: -136px;
        width: 299px;
    }
    .main_logo_nav_lis_image{
        width: 30px;
        height: 25px;
        display: block;
        margin: auto;
        margin-top: 10px;
    }
    .main_logo_nav_lis_p{
        width: 154px;
        height: 30px;
        text-align: center;
        border-bottom: 1px dashed #cbcbcb;
        font-size: 16px;
        color: #439ea3;
        margin-left: 0px;
        margin: auto;
        margin-top: 12px;
    }
    .main_logo_nav_lis_ps{
        font-size: 12px;
        color: #8c8c8c;
        line-height: 24px;
        margin-top: 0px;
        width: 180px;
        margin-left: 0px;
        margin: auto;
    }
    .main_background{
        width: 100%;
        height: 460px;
        background-color: #e6e8e9;
    }
    .main_content{
        width: 524px;
        height: 460px;
        margin: auto;
        padding-top: 17px;
    }
    .main_content::after{
        content: "";
        height: 0;
        visibility: hidden;
        display: block;
        clear: both;
    }
    .main_content_title{
        font-size: 18px;
        color: #000;
        text-align: center;
    }
    .main_content_imgs{
        width: 257px;
        height: 10px;
        display: block;
        margin: auto;
        margin-top: 13px;
    }
    .main_content_p{
        font-size: 14px;
        color: #666666;
        line-height: 30px;
        width: 200px;
        margin: 0;
        margin-top: 35px;
        float: left;
        margin-left: 0px;
    }
    .main_content_img{
        width: 267px;
        height: 0px;
        background-color: #e6e8e9;
        margin: 0;
        float: left;
        padding-top: 0px;
        margin-top: 0px;
        transform: translate(54px,-130px);
    }
    .main_content_img_one{
        width: 51px;
        height: 159px;
        margin-left: 4px;
        visibility: hidden;
    }
    .main_content_img_two,.main_content_img_four,.main_content_img_theer{
        width: 267px;
        height: 159px;
        margin-right: 18px;
    }
    .main_content_img_four{
        visibility: hidden;
    }
    .main_content_img_five{
        width: 72px;
        height: 159px;
        visibility: hidden;
    }
    .main_content2{
        width: 100%;
        height: 552px;
        margin: auto;
        padding-top: 17px;
    }
    .main_content2_background{
        background-color: #a4d1ee;
        height: 468px;
        width: 100%;
        margin-top: 20px;
    }
    .main_content2_background_uls{
        list-style-type: none;
        width: 216px;
        padding-top: 10px;
        margin: auto;
        float: none;
    }
    .main_content2_background_uls_lis{
        width: 104px;
        height: 36px;
        float: left;
    }
    .main_content2_background_uls_liss{
        width: 104px;
        height: 36px;
        margin-right: 6px;
        float: left;
    }
    .main_content2_background_uls_lis_p{
        font-size: 14px;
        color: #ffffff;
        text-align: center;
        line-height: 36px;
    }
    .main_content2_background_uls_lis:hover,.main_content2_background_uls_liss:hover{
        background-image: url("../05-练习页面响应式/-12.png");
    }
    .main_content2_background_uls_lis_p:hover{
        color: #7fc1f0;
    }
    .main_content2_background_uls::after,.main_content2_background_bottom::after{
        content: "";
        height: 0;
        display: block;
        clear: both;
        visibility: hidden;
    }
    .main_content2_background_bottom{
        width: 100%;
        margin: auto;
    }
    .main_content2_background_bottom_uls{
        list-style-position: inside;
        list-style-image: url("../05-练习页面响应式/-13.png");
        float: none;
        margin-left: 10px;
    }
    .main_content2_background_bottom_uls_lis{
        width: 500px;
        height: 40px;
        border-bottom: 1px dashed #f6fbfd;
        line-height: 40px;
    }
    .main_content2_background_bottom_uls_lis_link{
        text-decoration: none;
        font-size: 14px;
        color: #ffffff;
        margin-left: 30px;
    }
    .main_content2_background_bottom_uls_lis_link_spans{
        float: right;
        margin-right: 30px;
    }
    .main_content2_background_bottom_img{
        float: none;
        margin-top: 0px;
        width: 250px;
        height: 150px;
        display: block;
        transform: translate(160px,15px)
    }
    .main_content3{
        height: 800px;
        width: 100%;
        margin: auto;
        padding-top: 10px;
    }
    .kong{
        clear: both;
    }
    .main_content3_left{
        width: 430px;
        height: 410px;
        padding-top: 20px;
        float: none;
        margin: auto;
    }
    .main_content3_left_erwei{
        width: 121px;
        height: 168px;
        border: 1px solid #ebebeb;
        float: left;
        margin-left: 10px;
    }
    .main_content3_left_erwei_img{
        width: 90px;
        height: 90px;
        display: block;
        margin: auto;
        margin-top: 15px;
    }
    .main_content3_left_erwei_ps{
        font-size: 12px;
        color: #030303;
        line-height: 21px;
        text-align: center;
        margin-top: 14px;
    }
    .main_content3_left_uls{
        float: left;
        list-style-type: none;
    }
    .main_content3_left_uls_lis{
        margin-left: 20px;
        height: 16px;
        margin-bottom: 14px;
    }
    .main_content3_left_uls_lis_img{
        width: 22px;
        height: 18px;
        float: left;
    }
    .main_content3_left_uls_lis_p{
        float: left;
        font-size: 14px;
        color: #747474;
        margin-left: 15px;
        line-height: 18px;
    }
    .main_content3_left_image{
        width: 430px;
        height: 196px;
        margin-top: 4px;
    }
    .main_content3_left::after{
        content: "";
        height: 0;
        visibility: hidden;
        display: block;
        clear: both;
    }
    .main_content3::after{
        content: "";
        height: 0;
        visibility: hidden;
        display: block;
        clear: both;
    }
    .main_content3_right{
        float: none;
        margin-top: 0px;
        margin: auto;
        width: 430px;
    }
    .main_content3_right_nav{
        margin-bottom: 4px;
    }
    .main_content3_right_nav_content{
        font-size: 14px;
        color: #666666;
        float: left;
    }
    .main_content3_right_nav_text{
        width: 430px;
        height: 24px;
        border: 1px dashed #d4d2d2;
        background-color: #f9f8f8;
        margin-top: 5px;
        float: left;
    }
    .main_content3_right_nav_texts{
        width: 430px;
        height: 80px;
        border: 1px dashed #d4d2d2;
        background-color: #f9f8f8;
        margin-top: 6px;
    }
    .main_content3_right_nav_tijiao{
        width: 94px;
        height: 30px;
        background-color: #3c9cd3;
        border: 0px;
        margin-top: 12px;
    }
    .main_footer{
        height: 89px;
        width: 100%;
    }
    .main_footer_top{
        height: 54px;
        background-color: #3c9cd3;
    }
    .margin{
        width: 214px;
        margin: auto;
        padding-top: 6px;
    }
    .main_footer_top_p{
        color: #ffffff;
        float: left;
        font-size: 12px;
        margin-right: 18px;
    }
    .main_footer_top_img{
        float: left;
        margin-right: 20px;
        width: 24px;
        height: 20px;
    }
    .main_footer_top_uls{
        width: 400px;
        margin: auto;
        list-style-position: inside;
        color: #ffffff;
        font-size: 12px;
        margin-top: 6px;
    }
    .main_footer_top_uls_lis{
        float: left;
        margin-right: 6px;
    }
    .main_footer_top_uls_lis_link{
        text-decoration: none;
        color: #ffff;
        font-size: 12px;
        margin-left: -8px;
    }
    .main_footer_top_uls_liss{
        list-style-type: none;
        float: left;
        margin-right: 6px;
    }
    .main_footer_bottom{
        background-color: #1c1b29;
        height: 35px;
    }
    .main_footer_bottom_p{
        color: #ffffff;
        font-size: 12px;
        margin: auto;
        line-height: 35px;
        width: 434px;
    }
    .margin::after,.main_footer_top_uls::after{
        content: "";
        height: 0;
        visibility: hidden;
        display: block;
        clear: both;
    }
}